Insulating riser sleeve composition



Judy 30, 1968 M. E. BINKLEY 3,394,913

INSULATING RISER SLEEVE COMPOSITION Filed Oct. 23, 1965 RI SEE 5LEEVECompmsme, ASBESTOS FIBEK BENTONITE. CLAY DIATOMACEOUS EARTH AND BINDER0F ME AND/0R BAsnc MAGNESIUM CARBONATE.

\NVENTOR MARK E. BWKLEY ATrmA/EV United States Patent 3,394,913INSULATING RISER SLEEVE COMPOSITION Mark E. Binkley, Somerville, N.J.,assignor to Johns- Manville Corporation, New York, N.Y., a corporationof New York Filed Oct. 23, 1965, Ser. No. 504,230 6 Claims. (Cl.249-201) ABSTRACT OF THE DISCLOSURE A riser sleeve product for moltenmetal casting of an inorganic composition comprising asbestos fiber,bentonite clay, diatomaceous earth, and binder of lime and/or basicmagnesium carbonate.

This invention relates to improved riser sleeves for metal casting, andin particular to riser sleeves of improved compositions and the noveland advantageous riser sleeve products thereof.

Riser sleeves, which provide reservoir chambers for molten metal to feedthe same back into the mold cavity to compensate for shrinkage duringsolidification of the casting metal within the mold, have conventionallybeen constructed of gypsum plaster or of typical exothermic materials.Such materials however normally provide constructions which areinefiicient, lack resilience and durability. Moreover, the gypsumsleeves are frequently unsatisfactory in service and the exothermicmaterials are costly.

It is the primary object of this invention to provide new, low-cost andeffective riser sleeves products.

It is also a primary object of the invention to provide economical risersleeves which have high thermal insulating properties and are reuseableunder moderate applications and service conditions.

It is a further primary object of this invention to provide improvedriser sleeves which are useful with a variety of molten metals and arenot discernibly wetted or attacked by common molten metals and alloyssuch as brass, aluminum, etc.

These and other objects and advantages of this invention will becomemore apparent from the hereinafter detailed description thereof.

The drawing comprises a pictorial view illustrating a typicalcylindrical riser sleeve construction and product produced from thecomposition of this invention.

This invention comprises novel and improved riser sleeve productsconsisting of the heat treated or reacted products of a specificcombination of ingredients which upon exposure to apt thermal conditionsso cooperate or coact whereby the resultant composition or concertedeffects of the ingredients, or the thermal products thereof, provideenhanced and new beneficial properties and advantages appropriable tometal casting and in turn their use in riser sleeves of conventionalconfigurations and applications. The riser sleeves of this inventionessentially comprise and result from apt thermal treatments of thefollowing ingredients set forth both in the broadest and preferredrelative proportions therefor of the invention. The relative proportionsare expressed in approximate percentages by weight.

Beyond the said given proportions of ingredients suitable for thermalconversion into the products of this inven- 3,394,913 Patented July 30,1968 tion, it is considered essential that the combination thereofcontain at least one or the other enumerated lime or basic magnesiumcarbonate components as, or to efiect a binder system. For example, withno or insignificant quantities of basic magnesium carbonate as thesource of a binder the combination should include about 6 to 12% byweight of lime, and conversely with no or ineffective amounts of lime asthe source of a binder the combination could include about 6 to 12% byweight of basic magnesium carbonate, or the products embody up to about30% by weight of a combination thereof but preferably no more than about20%.

Moreover, to produce an effective riser sleeve product of new andimproved characteristics and of the precepts of this invention, theaforedefined combination of components, upon admixture, consolidationand shaping into a body of designed configuration and dimensionspursuant to common manufacturing procedures, must be fired or heattreated to a temperature greater than 1300 F. and under most allcircumstances preferably to about 1400 F. for maximum derivation ofbenefits, for periods of an hour or more depending, of course, upon themass of the given product, and normally for 3 to 6 hours, or longer.Higher temperatures can be applied, but the advantages or degree ofimprovements thereof attributable to any appreciable greatertemperatures are not particularly significant or commensurate with theeffort and therefore not recommended.

The riser sleeve products of this invention are effectively producedthrough the use of a water slurry or suspension as a medium for theadmixing and interaction of the components thereof. Preferably a diluteslurry of the solids in the aqueous medium is prepared, and to effect alow density material of subsequent high thermal insulating efficiencyand facilitate molding, the slurry of the essential combination ofingredients is heated to temperatures of at least F. up to 212 F. for /2hour or more to render the slurry of solids more amenable to shaping anddewatering into a self-sustained body of a low, dry density and withboth good green and fired strength. The basic magnesium carbonate, ifemployed, can be prepared pursuant to common means comprising, forexample, reacting a solution of magnesium hydroxide with carbon dioxide.

Consolidating and shaping of the slurried materials of the givencompositions to any suitable body configuration and dimensions such astwo half sections providing the conventional cylindrical sleeve can becarried out most effectively with a filter press. Other workable formingtechniques comprise plate and frame type filter presses, pan castingwith a relatively thicker or concentrated slurry, and like means. Theshaped articles are then dried in an oven to accelerate the process.

The thus prepared composition and shaped body thereof is finally heattreated by exposure to temperatures greater than 1300 F. and mostdesirably about 1400 F. over a period of at least one hour and moreeffectively about 4 or 5 hours, but depending upon the mass toeffectively heat soak the body throughout. The fired product, whichpossesses good thermal insulating properties, is neither wetted norattacked by common molten metals such as aluminum employed in typicalcasting operations. Moreover, it exhibits a minimum of splattering ofthe molten metal upon initial contact.

The following examples comprise illustrations of the preferred andtypical compositions of the riser sleeve products of this invention andmeans of manufacturing the same. It is to be understood that thespecific proportions or ratios and components of the compositions givenin the examples as well as the means, conditions, techniques, etc., setforth therein, are primarily exemplary and are not to be construed aslimiting this invention to 3 any specific ingredients or proportionsthereof and compositions or conditions other than those hereinbeforespecified as essential.

Example 1' Riser sleeves in complementary half-cylindrical sections,measuring 36 inches long and /2 inch thick with internal diameters of2.5, 3, 4 and 7 inches respectively, were produced from the followingcombination of ingredients:

Percent Basic magnesium carbonate 7.9 Bentonite clay 8.2 Asbestos fiber9.9 Diatomaceous earth (calcined) 73.7 Lime 0.3

The basic magnesium carbonate was prepared by gassing a magnesiumhydroxide solution with CO gas. All given components were thoroughlymixed in an aqueos medium and press filter molded to the givenconfigurations and sizes. The molded articles, following air drying,were fired at 1400 F. at hours to throughly heat soak the samethroughout their mass.

Example 2 Riser sleeve samples in like semior half-cylindrical sectionsand dimensions as given in Example 1 where also produced from thefollowing formulation:

Percent Diatomaceous earth (calcined) 65 Bentonite clay Asbestos fiber12 Hydrated lime 8 An aqueous slurry of an admixture of the saidingredients was heated and held for 1 hours at 200 F. to form a gel,then press filter molded to the stated sizes. The manufacturing processwas completed by firing the pressed and shaped products at 1400 F. for 5hours as in Example 1.

The correspondingly dimensioned half-cylindrical sections from each ofthe foregoing examples were mated to produce complete cylindricalsections with the given internal diameters, and bonded together witheither plastic or cloth tape, or steel straps. Samples of each weremounted in a vertical or upright position with the lower openingsuitably anchored in and closed with foundry sand and filled with moltenaluminum. They were unaffected by the molten metal, did not producesplattering of the aluminum, and upon solidification and removal of theformed metal ingot, appeared wholly intact and were reused. Similarriser sleeve samples were linkewise employed with molten iron, stainlesssteel and brass and were found to be highly effective and satisfactoryin all reused. Similar riser sleeve samples were likewise em- Additionalhalf-section samples were then cemented together with a high meltingpoint asphalt and when filled with a molten metal iron there wasbubbling and splattering of the metal adjacent the seams where theasphalt was present and which did not occur with the banded samples.

The thermal reaction compositions of this invention can conveniently andeffectively be produced and employed in half cylindrical sections. Theyprovide the novel riser sleeve products by uniting two complementarysections of like dimensions adjacent to each other to form a completecylinder with the internal channel forming the molten metal reservoir.The abutting segments may be secured to each other with plastic or clothtape, or metal straps which contain the same with adequate strength forthe intended service.

It will be understood that the foregoing details are given for purposesof illustration and not restriction, and

that variations within the spirit of this invention are to be includedwithin the scope of the appended claims.

What I claim is:

1. An improved riser sleeve for molten metal casting having a thermallydurable hollow body forming the reservoir chamber comprising thecomposition product of heating to a temperature greater than 1300 F. anadmixture comprising, in approximate percentages by weight:

Percent Asbestos fiber 520 Bentonite clay 5-20 Diatomaceous earth 50-90and at least one source of a binder selected from the group consistingof lime and basic magnesium carbonate in an approximate percentage byWeight of 6 to 30%.

2. An improved riser sleeve for molten metal casting having a thermallydurable hollow body forming the reservoir chamber comprising thecomposition product of heating to a temperature of at least about 1400F. an admixture comprising, in approximate percentages by weight:

Percent Asbestos fiber 8-15 Bentonite clay 8-15 Diatomaceous earth 60-80and at least one source of a binder selected from the group consistingof lime and basic magnesium carbonate in an approximate percentage byweight of 6 to 20%.

3. The improved riser sleeve product of claim 2 wherein the lime contentis approximately 6 to 12% by weight.

4. The improved riser sleeve product of claim 2 wherein the basicmagnesium carbonate content is approximately 6 to 12% by weight.

5. An improved riser sleeve for molten metal casting having a thermallydurable hollow body forming the reservoir chamber comprising thecomposition product of heat treating at a temperature of at least about1400 F. over a period of in excess of about 3 hours an admixtureconsisting essentially, in approximate percentages by weight, of:

Percent Asbestos fiber 8-15 Bentonite clay 8-15 Diatomaceous earth 60-80Lime 6-12 6. An improved riser sleeve for molten metal casting having athermally durable hollow body forming the reservoir chamber comprisingthe composition product of heat soaking at a temperature of at leastabout 1400" F. for a period in excess of about 3 hours an admixtureconsisting essentially, in approximate percentages by weight, of:

Percent Asbestos fiber 8-15 Bentonite clay 8-15 Diatomaceous earth 60-80Basic magnesium carbonate 6-12 References Cited UNITED STATES PATENTS2,156,980 5/1939 Groninger 24920l 3,072,981 1/ 1963 Davidson 249-201 X3,212,749 10/ 1965 La Bate 106-383 X 3,230,056 l/1966 Arant et allO6-38.22 X 3,262,165 7/ 1966 Ingham 24.9-197 X FOREIGN PATENTS 998,6997/1965 Great Britain.

I. SPENCER OVERHOLSER, Primary Examiner.

E. MAR, Assistant Examiner.

